The present invention relates to the field of electrical components and is to be applied in the structural realization of a gas discharge arrester provided with an air gap connected in parallel. This air gap is formed by a voltage-carrying electrode of the arrester, an auxiliary electrode at ground potential, and an insulating foil disposed between the electrode and auxiliary electrode and provided with openings.
In a known gas discharge overvoltage arrester with an air gap connected in parallel, the arrester consists of a tubular ceramic insulator and two electrodes disposed at the ends of the ceramic insulator. For the formation of a spark gap, the arrester is surrounded by a metal part in the form of a basket and in contact with the first electrode of the arrester and leads the potential of this electrode to the vicinity of the second electrode; placed on the second electrode is an insulating disk provided with openings, and on this insulating disk a metal disk is disposed in contact with the basket-like metal part and forms an auxiliary electrode. This auxiliary electrode has arches protruding into the openings of the insulating disk and is fixed in its position by means of an insulating fastening disk press-fitted on the contact cylinder of the second electrode. Centering of the arrester inside the basket-like metal part is done by means of the insulating disk, the outside diameter of which is greater than the outside diameter of the arrester and of the auxiliary electrode (DE-OS-A1-29 51 467).
In another known gas discharge overvoltage arrester with an air gap connected in parallel, the auxiliary electrode is formed by a metal ring which applies, with interposition of an insulating ring, against the flange-like bottom of a contact part connected to one electrode. The auxiliary electrode is electrically connected with the other electrode of the arrester via a basket-like metal part. Between the auxiliary electrode and the counter-electrode of the arrester is an insulating disk which centers the arrester inside the metal sleeve and at the same time insulates the counter-electrode from this basket-like metal part. In this arrester the ceramic insulator of the arrester is formed as a cylindrical tube of constant wall thickness, the outside diameter of the electrode and the outside diameter of the ceramic insulator being the same.
In a further known overvoltage arrester with an air gap connected in parallel, the auxiliary electrode is formed by a metal cap press-fitted on the ceramic insulator. To this end the diameter of the ceramic insulator is chosen greater than the outside diameter of the two electrodes of the arrester and the ceramic insulator is chamfered at its ends to achieve a flush transition to the electrodes (DE-A1-31 18 137).